The prior art describes numerous processes detailing the isolation of desired biological targets from bodily fluids. As discussed in the prior art, a biological entity of interest typically is derived from a sample that is removed from a donor, which sample contains a heterogeneous mixture of cells and other biological substances. These substances span a size scale from the macroscopic to the molecular. The heterogeneous sample is subjected to one or more separation and purification procedures in order to obtain a preparation that is enriched with the biological target. Typical heterogeneous samples from which a biological target may be derived include: peripheral whole blood, bone marrow, tumor tissue, sputum, lymphatic fluid, ascites fluid, pleural fluid, spinal fluid, urine, gastro-intestinal fluid, bile, umbilical cord blood, amniotic fluid and so forth. Often, the amount of the biological entity of interest in the sample is negligible. Therefore, the target cell, stem cells, metastatic cancer cells, viruses, prion, and so forth, must be separated and purified from an overwhelming number of very similar, often nearly identical, non-target biological entities and other unwanted biological substances. Methods for separating and purifying cells and other biological entities have been developed. So-called positive separation methods take advantage of immunoaffinity-based technology. In an immunoaffinity-based method, antibody specific for a biological entity, for example a cell-type of interest, is linked to the surface of a solid such as a particle or filtration membrane. The captured cells, that is, cells bound to the solid through bonding to the antibody, are then separated from non-bound cells by filtration, adsorption on a column, partitioning in a magnetic field, centrifugation, and so on.
International application WO09944583 describes an implantable porous device used for isolating and/or stimulating the immune response within an individual that can also be used to sequester immune cells, which can later be introduced to the body. A primary embodiment of this invention is the implantation of a porous/permeable structure contained within an impermeable structure. The porous structure contains an antigen to initiate a humoral immune response. Diseased immune cells can also be sequestered within the device and caused to undergo apoptosis via specific cytokine initiation (p. 12, line 20). Immune cells may then be captured within the porous membrane, the device extracted and the cells later introduced within the body. It is disclosed that immune cells can be isolated and later used for various immunotherapy treatments (p. 13-14).
A continuous-flow immunoaffinity method for separating target cells from non-target cells in whole blood withdrawn from a donor is described in U.S. Pat. No. 6,221,315. In this method target cells bind to dense, target cell specific particles that are then centrifuged and, thereby, the target cells are separated from non-bound cells.
A method for isolating metastatic cancer cells from donated blood is described in PCT Publication WO 0220825.
A capillary apparatus and associated immunoaffinity method for separating target cells from cells in a mixture is described in PCT Publication WO 0068689.
In PCT Publication WO 0162895, methods for concentrating and expanding T-cells are described, which methods depend upon binding of T-cells to co-stimulatory ligands attached to a surface. T-cells are derived from circulating blood obtained from an individual by apheresis or leukapheresis. In one embodiment of the disclosed methods, paramagnetic particles having attached ligands specific for the target cell surface moiety that induces cell stimulation are introduced into an animal. As stated in the PCT Publication, a magnetic field may be applied to a discrete region of the animal to induce localization and stimulation of the target cells bound to the particles at the discrete region.
Stem cells are cells capable of both indefinite proliferation and differentiation into specialized cells that serve as a continuous source for new cells for such tissues as blood, myocardium, liver, etc. Hematopoietic cells are rare, pluripotent cells, having the capacity to give rise to all lineages of blood cells. Stem cells undergo a transformation into progenitor cells, which are the precursors of several different blood cell types, including erythroblasts, myeloblasts, monocytes and macrophages. Stem cells have a wide range of potential applications, particularly in the autologous treatment of cancer patients.
Typically, stem cell products (true stem cells, progenitor cells and CD34+ cells) are harvested from bone marrow of a donor in a procedure, which may be a painful, and requires hospitalization and general anesthesia. More recently, methods have been developed enabling stem cells and committed progenitor cells to be obtained from donated peripheral blood or peripheral blood collected during a surgical procedure.
Progenitor cells, whether from bone marrow or peripheral blood, can be used to enhance the healing of damaged tissues, such as myocardium damaged by myocardial infarction, as well as enhance hematologic recovery following an immunosuppressive procedure such as chemotherapy.
A number of immunotherapy strategies for treating cancer patients have been under development. These include (1) adoptive immunotherapy using different types of stimulated autologous cells, (2) systemic transfer of allogeneic lymphocytes, (3) vaccination at a distant site to generate a systemic tumor-specific immune response, and (4) implantation of immune cells directly into a tumor.
In adoptive immunotherapy, cells isolated from peripheral blood withdrawn from a patient are stimulated and then returned to the same patient; thus, the cells are histocompatible. The autologous lymphocytes may be stimulated ex-vivo with tumor-associated antigen to make them tumor-specific (Zarling et al. (1978) Nature 274:269-71 and U.S. Pat. No. 5,192,537) or autologous lymphocytes and killer cells can be stimulated non-specifically as described in U.S. Pat. No. 5,308,626. The entire disclosure of each of these United States patents is hereby incorporated by reference into this specification.
Peripheral blood-derived lymphocytes cultured in the presence of interleukin-2 form lymphokine-activated killer (LAK) cells, which have been used to treat individuals suffering from metastatic melanoma and renal cell carcinoma (Rosenberg (1987) New Engl. J. Med. 316:889-897). LAK cells have also been used to treat brain tumors (Merchant et al. (1988) Cancer 62:665-671 and (1990) J. Neuro. Oncol. 8:173-198).
Another form of adoptive immunotherapy involves the use of autologous tumor-infiltrating lymphocytes (TIL) (Rosenberg et al. (1990) New Engl. J. Med. 323:570-578). Unfortunately, a clinically useful quantity of TILs from a donor can only be obtained and prepared in a limited number of tumor types.
In adoptive transfer of allogeneic lymphocytes, lymphocytes obtained from a donor are used to induce a general level of immune stimulation against tumors (Strausser et al. (1981) J. Immunol. Vol. 127, No. 1, Zarling et al. (1978) Nature 274:269-71 and Kondo et al. (1984) Med Hypotheses 15:241-77).
The third immunotherapy strategy listed above, involves generating an active systemic tumor-specific immune response of host origin by administering a vaccine composition (tumor-antigen vaccines and anti-idiotype vaccines) at a site distant from the tumor.
Another approach involves using tumor cells derived from a donor to be treated (Schirrmacher et al. (1995) J. Cancer Res. Clin. Oncol. 121:487-489 and U.S. Pat. No. 5,484,596).
Autologous tumor cells have been used in combination with allogeneic cytokine-secreting cells in treating cancers, as described in PCT Publication WO 98/16238.
The fourth immunotherapy strategy listed above, intra-tumor implantation, involves delivering effector cells in proximity to a tumor site. Different effector-cell types (syngeneic lymphocytes, non-adherent LAK cells, adherent LAK cells, syngeneic cytotoxic T lymphocytes (CTL) raised against tumor antigens, and allogeneic CTL raised against alloantigens) have shown success in a rat gliosarcoma cell line (Kruse et al. (1990) Proc. Natl. Sci. USA, 87:9377-9381).
The T-cell antigen receptor (TCR) is a multisubunit immune recognition receptor that associates with the CD3 complex and binds to peptides presented by the major histocompatibility complex (MHC) class I and II proteins on the surface of antigen-presenting cells (APCs). Binding of TCR to the antigenic peptide on the APC is the central event in T-cell activation. A requirement for MHC-matched APCs as accessory cells for T-cell stimulation is problematic because APCs are relatively short-lived and, therefore, in a long-term culture system they must be continually obtained from a donor and replenished.
The isolation and use of dendritic cells from donated human peripheral blood in immunotherapy methods for treating prostate cancer is described in U.S. Pat. No. 5,788,963.
The use of hematopoietic and cardiac stem cells for regenerating damaged myocardium is described in PCT Publication WO 209650.
The use of human umbilical blood as a source of neural cells for transplantation is described in PCT Publication WO 0166698.
Clearly, a need exists for providing many different endogenous cell-types, infected or uninfected, from human and non-human donors for use in numerous and varied human and veterinary research, diagnostic and therapeutic applications. Endogenous cells from a donor, in general, may be used for genetic screening purposes in birth disorders or in organ replacement therapy.
A need exists for capturing circulating cells, such as cancer cells with the potential to metastasize, viruses, bacteria, prions and other biological entities. This need encompasses research, diagnostics and therapeutics applications in diverse disciplines including, genetics, hematology, microcirculation, oncology, infectious disease, immunology and microbiology.
There exists a need for obtaining cellular samples from donors that are enriched in the desired biological target. Because a heterogeneous sample contains a negligible amount of a biological entity of interest, the limits of separation methods to provide viable and potent biological target in sufficient purity and amount for research, diagnostic or therapeutic use are often exceeded. Because of the low yield after separation and purification, some cell-types, such as stem cells, progenitor cells and immune cells (particularly T-cells) must be placed in long-term culture systems under conditions that enable cell viability and clinical potency to be maintained and under which cells can propagate (cell expansion). Such conditions are not always known. In order to obtain a sufficient amount of a biological target, a large amount of a sample, such as peripheral blood, must be obtained from a donor at one time, or samples must be withdrawn multiple times from a donor and then subjected to one or more lengthy, expensive, and often low-yield separation procedures to obtain a useful preparation of the biological target. Taken together, these problems place significant burdens on donors, separation methods, laboratory personnel, clinicians and patients. These burdens significantly add to the time and costs required to isolate the desired cells.
There exists a need for obtaining cells from non-humans, which cells comprise particular antigens or antibodies of interest. The transcription and translation levels of any number of constituents, mechanical properties, in vitro memory properties or genetic properties of cells can be analyzed. Capturing immune cells, stem cells and committed progenitor cells, and metastatic cancer cells, blood borne viruses are of particular interest.
There exists a need for devitalizing circulating cells to minimize their potential to induce or promote disease in the host.
It is an object of this invention to provide a sample directly from a donor, which sample is enriched or sufficiently enriched with biological target.
It is an object of this invention to provide an implantable target specific capture device that enables easy and repeated access in order to obtain samples when desired, without requiring removal of the device from a donor, which samples are enriched with the target of interest.
It is an object of this invention to provide a capture device that could be configured to simultaneously capture multiple targets (e.g. multiple types of metastatic cancer cells).
It is an object of this invention to provide a capture device that could be easily modified to enable it to capture different types of cells.
It is an object of this invention to provide a capture device that could capture, sequester, and maintain the viability of the captured cells until the cells are harvested.
It is an object of this invention to provide a capture device that could devitalize (i.e. destroy) the captured cells, such as metastatic cancer cells or HIV-infected cells, particularly without the need for additional interactions from the host.
These and other objects afforded by the methods and implantable target specific capture devices of the invention will become evident upon consideration of the following drawings, summary and detailed description.